What is CRM in Odoo?

I work with Odoo CRM as a programmer and as developer. We have a dialogue with the client, looking for their needs and we provide the service, including accounting, to fulfill the need. Odoo can be used as a cloud service, but we host in-house. Some clients choose to do the hosting themselves. We hep the client to find a working solution and if modules and wishes are missing, we create modules to fill the gap. Our clients are small start ups with almost no turnover as well as large organizations with millions in turnover.